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An Uneasy Future for Tropical Storm Emily

By: Dr. Jeff Masters, 8:48 AM GMT on August 02, 2011

As of 5AM EDT, Tropical Storm Emily was located at 15.5N, 64.0W, moving W at 16 mph with sustained winds of 40 mph. It's central pressure was estimated to be 1006 mb. Satellite imagery shows that the convection around Emily's center continues to grow, with large amounts of cold anvil cirrus. However, satellite analysis of cloud-top winds suggest that Emily still has an elongated circulation, more like that of a jelly-bean than the compact circulation which is more favorable for intensification. Also, while Emily is in a low-shear region, there are large areas of wind shear to it's immediate north and south. The dry air of the Saharan Air Layer is just north of Emily, which would weaken the storm.


Figure 1 IR Satellite image of TS Emily taken at 3AM EDT August 2, 2011



Forecasting Emily
Model uncertainty is still high for forecasting Emily's track. The 00Z CMC and NOGAPS global models keep Emily on a western track, before recurving to make landfall on the western coast of Florida. The 00Z HWRF and GFDL dynamic
hurricane models both have Emily approaching the eastern coast of Florida, but recurving sharply to the northeast before making landfall. However, the premier global models, GFS and ECMWF, suggest that forecasters should be very cautious.
The 12Z ECMWF did not get a good representation of Emily in its starting conditions, so the forecast Emily did not gain strength and drifted westwards, missing Hispanola. The 00Z GFS does not have any forecast features that could be reasonably associated with Emily in my judgement. From what I can tell, the GFS moves Emily's circulation over Hispanola and Emily then never has a chance to organize. This is disconcerting since the previous 4 runs of the GFS had produced a reasonably robust tropical cyclone with winds near or just exceeding hurricane strength.

Even though the tracks produced by these models are different in their long-term outlooks, they all suggest that Emily will pass by Hispanola close enough for that island's mountains to impact the storm's winds and thus dampen any intensification. However, the 00Z NAM model does not bring Emily near the island, and keeps it moving westwards into the Caribbean sea as a well-organized storm. This, combined with the widely different solutions discussed previously, suggests that people across the Caribbean and living along the Gulf coast should keep an eye on this storm for the next several days.

I would prefer to make an intensity forecast for Emily after it has cleared the island of Hispanola and it's tall mountains. Many storms have weakened considerably after passing by there, and some have dissipated (TS Cindy in 1993, for example).

In light of this uncertainty, the NHC forecast hasn't changed that much. Emily is forecast to turn towards the northwest, making landfall somewhere in southeastern Florida on Saturday as a weak hurricane. (5AM EDT update NHC has adjusted their forecast to the east, so Emily does not make landfall in the next 5 days. Also, Emily does not reach hurricane strength in this forecast.) Tropical storm warnings have been issued for Puerto Rico and the Dominican Republic. A tropical storm watch has been issued for Haiti.


Figure 2 Official five-day track forecast for Tropical Storm Emily.

Angela will have a full post later today discussing Emily.

Thanks for reading,

Dr. Rob Carver

The views of the author are his/her own and do not necessarily represent the position of The Weather Company or its parent, IBM.

Reader Comments

1501. WxLogic
12Z HWRF... Just like CMC but stronger (not surprised there).
You can see that the LLC is on the western side of the convection on Rapid Scan. Watch the low level clouds to the west of the main convection. Emily remains somewhat disorganized for now.

Link
Weaker the storm, the west she blows
1504. Levi32
Quoting WeatherNerdPR:
They're actually expecting TS conditions in PR?
HAZARDS AFFECTING LAND
----------------------
WIND...TROPICAL STORM CONDITIONS ARE EXPECTED IN PUERTO RICO...
CULEBRA...AND VIEQUES LATER TODAY AND TONIGHT...AND IN THE DOMINICAN
REPUBLIC AND HAITI ON WEDNESDAY. TROPICAL STORM CONDITIONS ARE
POSSIBLE IN THE U.S. VIRGIN ISLANDS LATER TODAY.

RAINFALL...EMILY IS EXPECTED TO PRODUCE TOTAL RAIN ACCUMULATIONS
OF 2 TO 4 INCHES IN THE NORTHERN WINDWARD ISLANDS AND LEEWARD
ISLANDS. TOTAL RAIN ACCUMULATIONS OF 4 TO 6 INCHES ARE EXPECTED IN
PUERTO RICO...THE DOMINICAN REPUBLIC...AND HAITI WITH ISOLATED
MAXIMUM AMOUNTS OF 10 INCHES POSSIBLE. THESE RAINS COULD CAUSE
LIFE-THREATENING FLASH FLOODS AND MUD SLIDES IN AREAS OF
MOUNTAINOUS TERRAIN.

STORM SURGE...A STORM SURGE WILL RAISE WATER LEVELS BY 1 TO 2 FEET
ABOVE NORMAL TIDE LEVELS IN THE TROPICAL STORM WARNING AREA. NEAR
THE COAST...THE SURGE WILL BE ACCOMPANIED BY LARGE AND DANGEROUS
WAVES.


NEXT ADVISORY
-------------
NEXT COMPLETE ADVISORY...500 PM AST.

$$
FORECASTER AVILA


Very possible given how far out the TS-force winds extend to the northeast of the center.
Recon finding 55+ MPH winds. Emily's getting good.
Morning everybody

I see Emily is still not a very impressive tropical storm, despite the nice satellite presentation. Last night I was thinking this would look a lot nicer in the morning, but that just goes to show you why it's not a good idea to make assumptions about what's going on underneath the cloud tops in the absence of recon or visible satellite imagery. Recon's findings are very unimpressive, and on CIMSS analysis the mid level circulation appears to still be displaced over the mid level circulation. So it is clear this storm is still having organization issues. Dry air is a bit of an issue, and additionally, convection remains favored on the east side due to greater divergence (TUTT) and greater convergence (trade winds) on this side. Still, divergence, convergence, shear, SSTs and moisture all remain favorable for continued intensification. Additionally, upper level winds will improve to the NW as the TUTT to the north backs out eastward.

As far as track, Emily should continue WNW into Hispaniola. Model consensus points to a crossing over central or eastern Hispaniola which is the more mountainous side, so significant weakening should occur. The track of Emily should become slightly more northward in response to the trough and then become more westward again in response to some light ridging building back in behind the trough. Track and intensity after Hispaniola remain hard to say because a lot will depend on just how good/bad Emily looks after crossing Hispaniola's 10,000ft mountains. Regardless, strong zonal flow over the east coast (W to E) will eventually recurve this system out strongly so the NE US shouldn't really be worrying about this. After Hispaniola and Cuba, the Bahamas and Florida will be the areas which will need to keep eye on this most. Also, I don't think too much intensification will occur upon passing Hispaniola. Dry air, shear, and upper divergence will all become less favorable as it approaches the massive ridge over the US.
Hey Miami I may be wrong here rookie at this but if it keeps going west wont that change the cone to the left or west
Quoting ChrisDcat5Storm:
IT looks like its heading wnw

Yep. It's beginning it's turn.
Levi, do you think models will continue moving east, or start shifting a bit to the west?
Quoting hurricanejunky:
My analogue for Emily was David 1979...




Emily is almost taking a similar track.
Quoting patrikdude2:


Odd, they say TS conditions are expected in PR, and then their map says there is only a 10-20% chance.
Again, Emily is kind of fat. Better than yesterday, but fat.
Heading west at 12 mph. When does this sharp northwards turn towards Hispaniola start? I know there's a trough up there, somewhere, but it's having very little influence, so far. Surprised the latest track forecast still takes it through Hispaniola. How much longer does it have to go west for them to make it a Cuba storm?
For 60 miles to the SW of the center, recon's finding nothing but 0-10kts out of the SSW.

Weird.
1516. Levi32
Quoting Hurricanes12:
Levi, do you think models will continue moving east, or start shifting a bit to the west?


I don't forecast the models. I forecast the storm. If I ever talk about models possibly shifting in the future, I am talking about their "need" to shift to where I think the storm will go, because eventually they would be forced to.
She's hesitating, she stopped, now back up running, gonna sidewap the cornerback which is the trough and pull a nice smooth one a lil later and then it's westbound down the sidelines to SCORE
Do we know how many vortices are under the mid level circulation with any degree of certainty?
OT: The drought in Texas caused a lake to dry up enough that it appears they've found another large piece of Space Shuttle Columbia.
Link
1506 "I don't think too much intensification will occur upon passing Hispaniola. Dry air, shear, and upper divergence will all become less favorable as it approaches the massive ridge over the US."

Strongly disagree.
its moving slightly North of due West as they have been predicting for today.

from the NHC at 11am discussion: THE CYCLONE SHOULD RESUME A WEST TO WEST-NORTHWEST TRACK
AT ABOUT 10 KNOTS TODAY
Quoting WeatherNerdPR:
They're actually expecting TS conditions in PR?
HAZARDS AFFECTING LAND
----------------------
WIND...TROPICAL STORM CONDITIONS ARE EXPECTED IN PUERTO RICO...
CULEBRA...AND VIEQUES LATER TODAY AND TONIGHT...AND IN THE DOMINICAN
REPUBLIC AND HAITI ON WEDNESDAY. TROPICAL STORM CONDITIONS ARE
POSSIBLE IN THE U.S. VIRGIN ISLANDS LATER TODAY.

RAINFALL...EMILY IS EXPECTED TO PRODUCE TOTAL RAIN ACCUMULATIONS
OF 2 TO 4 INCHES IN THE NORTHERN WINDWARD ISLANDS AND LEEWARD
ISLANDS. TOTAL RAIN ACCUMULATIONS OF 4 TO 6 INCHES ARE EXPECTED IN
PUERTO RICO...THE DOMINICAN REPUBLIC...AND HAITI WITH ISOLATED
MAXIMUM AMOUNTS OF 10 INCHES POSSIBLE. THESE RAINS COULD CAUSE
LIFE-THREATENING FLASH FLOODS AND MUD SLIDES IN AREAS OF
MOUNTAINOUS TERRAIN.

STORM SURGE...A STORM SURGE WILL RAISE WATER LEVELS BY 1 TO 2 FEET
ABOVE NORMAL TIDE LEVELS IN THE TROPICAL STORM WARNING AREA. NEAR
THE COAST...THE SURGE WILL BE ACCOMPANIED BY LARGE AND DANGEROUS
WAVES.


NEXT ADVISORY
-------------
NEXT COMPLETE ADVISORY...500 PM AST.

$$
FORECASTER AVILA
Quoting Levi32:


Very possible given how far out the TS-force winds extend to the northeast of the center.

Thanks. But with it passing 100+ miles to the south, and it's windfield being ~70 miles in diameter (maybe 80 at closest approach), still don't see it doing much wind-wise to PR.
Levi u seeing this WNW movement also
1527. ncstorm
Link

II. WIND SPEED PROBABILITY TABLE FOR SPECIFIC LOCATIONS

CHANCES OF SUSTAINED (1-MINUTE AVERAGE) WIND SPEEDS OF AT LEAST
...34 KT (39 MPH... 63 KPH)...
...50 KT (58 MPH... 93 KPH)...
...64 KT (74 MPH...119 KPH)...
FOR LOCATIONS AND TIME PERIODS DURING THE NEXT 5 DAYS

PROBABILITIES FOR LOCATIONS ARE GIVEN AS IP(CP) WHERE
IP IS THE PROBABILITY OF THE EVENT BEGINNING DURING
AN INDIVIDUAL TIME PERIOD (INDIVIDUAL PROBABILITY)
(CP) IS THE PROBABILITY OF THE EVENT OCCURRING BETWEEN
12Z TUE AND THE FORECAST HOUR (CUMULATIVE PROBABILITY)

PROBABILITIES ARE GIVEN IN PERCENT
X INDICATES PROBABILITIES LESS THAN 1 PERCENT
PROBABILITIES FOR 34 KT AND 50 KT ARE SHOWN AT A GIVEN LOCATION WHEN
THE 5-DAY CUMULATIVE PROBABILITY IS AT LEAST 3 PERCENT.
PROBABILITIES FOR 64 KT ARE SHOWN WHEN THE 5-DAY CUMULATIVE
PROBABILITY IS AT LEAST 1 PERCENT.


- - - - WIND SPEED PROBABILITIES FOR SELECTED LOCATIONS - - - -

FROM FROM FROM FROM FROM FROM FROM
TIME 12Z TUE 00Z WED 12Z WED 00Z THU 12Z THU 12Z FRI 12Z SAT
PERIODS TO TO TO TO TO TO TO
00Z WED 12Z WED 00Z THU 12Z THU 12Z FRI 12Z SAT 12Z SUN

FORECAST HOUR (12) (24) (36) (48) (72) (96) (120)
- - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - -
LOCATION KT

CAPE HATTERAS 34 X X( X) X( X) X( X) X( X) 1( 1) 2( 3)

MOREHEAD CITY 34 X X( X) X( X) X( X) X( X) 1( 1) 3( 4)

WILMINGTON NC 34 X X( X) X( X) X( X) X( X) 1( 1) 4( 5)

COLUMBIA SC 34 X X( X) X( X) X( X) X( X) 1( 1) 2( 3)

MYRTLE BEACH 34 X X( X) X( X) X( X) X( X) 1( 1) 5( 6)

CHARLESTON SC 34 X X( X) X( X) X( X) X( X) 1( 1) 5( 6)

AUGUSTA GA 34 X X( X) X( X) X( X) X( X) 1( 1) 2( 3)

SAVANNAH GA 34 X X( X) X( X) X( X) X( X) 2( 2) 4( 6)

MAYPORT NS 34 X X( X) X( X) X( X) X( X) 4( 4) 6(10)

JACKSONVILLE 34 X X( X) X( X) X( X) X( X) 3( 3) 6( 9)
TROPICAL STORM EMILY INTERMEDIATE ADVISORY NUMBER 4A
NWS NATIONAL HURRICANE CENTER MIAMI FL AL052011
200 PM AST TUE AUG 02 2011

...EMILY BACK ON TRACK...


SUMMARY OF 200 PM AST...1800 UTC...INFORMATION
----------------------------------------------
LOCATION...15.6N 64.8W
ABOUT 215 MI...345 KM SSE OF SAN JUAN PUERTO RICO
MAXIMUM SUSTAINED WINDS...45 MPH...70 KM/H
PRESENT MOVEMENT...W OR 280 DEGREES AT 12 MPH...19 KM/H
MINIMUM CENTRAL PRESSURE...1006 MB...29.71 INCHES


WATCHES AND WARNINGS
--------------------
CHANGES WITH THIS ADVISORY...

NONE.

SUMMARY OF WATCHES AND WARNINGS IN EFFECT...

A TROPICAL STORM WARNING IS IN EFFECT FOR...
* PUERTO RICO...VIEQUES AND CULEBRA
* THE DOMINICAN REPUBLIC
* HAITI

A TROPICAL STORM WATCH IS IN EFFECT FOR...
* U.S. VIRGIN ISLANDS

FOR STORM INFORMATION SPECIFIC TO YOUR AREA IN THE UNITED
STATES...INCLUDING POSSIBLE INLAND WATCHES AND WARNINGS...PLEASE
MONITOR PRODUCTS ISSUED BY YOUR LOCAL NATIONAL WEATHER SERVICE
FORECAST OFFICE. FOR STORM INFORMATION SPECIFIC TO YOUR AREA OUTSIDE
THE UNITED STATES...PLEASE MONITOR PRODUCTS ISSUED BY YOUR NATIONAL
METEOROLOGICAL SERVICE.


DISCUSSION AND 48-HOUR OUTLOOK
------------------------------
AT 200 PM AST...1800 UTC...THE CENTER OF TROPICAL STORM EMILY WAS
ESTIMATED FROM AN AIR FORCE PLANE TO BE NEAR LATITUDE 15.6 NORTH...
LONGITUDE 64.8 WEST. EMILY HAS RESUMED A WESTWARD MOTION AT 12
MPH...19 KM/H. ON THE FORECAST TRACK...THE CENTER OF EMILY WILL BE
NEAR THE COAST OF HISPANIOLA ON WEDNESDAY.

MAXIMUM SUSTAINED WINDS HAVE INCREASED AND ARE NOW NEAR 45 MPH...70
KM/H...WITH HIGHER GUSTS. SLIGHT STRENGTHENING IS ANTICIPATED
DURING THE NEXT DAY OR TWO.

TROPICAL STORM FORCE WINDS EXTEND OUTWARD UP TO 70 MILES...110 KM
FROM THE CENTER...MAINLY TO THE NORTH AND EAST OF THE CENTER.

LATEST MINIMUM CENTRAL PRESSURE REPORTED BY AN AIR FORCE
RECONNAISSANCE PLANE WAS 1006 MB...29.71 INCHES.


HAZARDS AFFECTING LAND
----------------------
WIND...TROPICAL STORM CONDITIONS ARE EXPECTED IN PUERTO RICO...
CULEBRA...AND VIEQUES LATER TODAY AND TONIGHT...AND IN THE DOMINICAN
REPUBLIC AND HAITI ON WEDNESDAY. TROPICAL STORM CONDITIONS ARE
POSSIBLE IN THE U.S. VIRGIN ISLANDS LATER TODAY.

RAINFALL...EMILY IS EXPECTED TO PRODUCE TOTAL RAIN ACCUMULATIONS
OF 2 TO 4 INCHES IN THE NORTHERN WINDWARD ISLANDS AND LEEWARD
ISLANDS. TOTAL RAIN ACCUMULATIONS OF 4 TO 6 INCHES ARE EXPECTED IN
PUERTO RICO...THE DOMINICAN REPUBLIC...AND HAITI WITH ISOLATED
MAXIMUM AMOUNTS OF 10 INCHES POSSIBLE. THESE RAINS COULD CAUSE
LIFE-THREATENING FLASH FLOODS AND MUD SLIDES IN AREAS OF
MOUNTAINOUS TERRAIN.

STORM SURGE...A STORM SURGE WILL RAISE WATER LEVELS BY 1 TO 2 FEET
ABOVE NORMAL TIDE LEVELS IN THE TROPICAL STORM WARNING AREA. NEAR
THE COAST...THE SURGE WILL BE ACCOMPANIED BY LARGE AND DANGEROUS
WAVES.


NEXT ADVISORY
-------------
NEXT COMPLETE ADVISORY...500 PM AST.

1529. twooks
12Z Euro kills it within 48 hours...

48



24


Quoting HurricaneSwirl:


Odd, they say TS conditions are expected in PR, and then their map says there is only a 10-20% chance.
The map is based on 8AM forecast, it could have changed a bit by now.
Models shifted West...

Emily is still moving west
Quoting MeterologyStudent56:
Now i think its Finally Safe to say this will not have a Direct Impact on South Florida as the Models are shifting East


Ummm, it can easily change.
Quoting tropicfreak:


Ummm, it can easily change.


The 2PM Models are coming in soon correct?
Quoting wunderkidcayman:
Emily is still moving west




I asked should the track move west if it keeps going west
Quoting MeterologyStudent56:
Models shifted West...



are theese reliable sorces ?
It would only make sense if it keeps going west track has to move west
the models shifted back west is this true?
Quoting MeterologyStudent56:
Models shifted West...


those are the 8am models.

the latest GFS, CMC, GFDL have all shifted east and keep it east of FL.
Quoting ChrisDcat5Storm:
the models shifted back west is this true?

no it's not. not sure why someone would post the 8am models when the 2pm models will be out soon.
Quoting chevycanes:

no it's not. not sure why someone would post the 8am models when the 2pm models will be out soon.


can i get the best and easyest to navagate site were i can find the models plz
Link
GFDL and UKM are the most recent runs. the bam models should update soon to 18z
Quoting yonzabam:
Heading west at 12 mph. When does this sharp northwards turn towards Hispaniola start? I know there's a trough up there, somewhere, but it's having very little influence, so far. Surprised the latest track forecast still takes it through Hispaniola. How much longer does it have to go west for them to make it a Cuba storm?
i think the storm is going 280 degrees at 10kts, it would not require a sharp turn to zero in on Hispaniola, what maybe to 285 or 290 degrees
According to the recent recon pass, Emily has a broad LLC.
1545. DVG
Quoting chevycanes:

no it's not. not sure why someone would post the 8am models when the 2pm models will be out soon.


Does the time and date stamp not say 14:21 EDT? They look west to me.?

Using the funktop sat imagery, it looks as if the storm is moving 1 degree west about every 7 hours. Looking at the green appearing as what I think is the center and following that west ( although the green has gone away and I used the lighter red )is how I came to that conclusion. If I am right ( I'll appreciate any disagreement ) then it actually wobbled a slight bit s of due west.
Link




S.FL is a-ok
GFS shifting far east as well...

Quoting ChrisDcat5Storm:
Link




S.FL is a-ok


For the moment.
Quoting DVG:


Does the time and date stamp not say 14:21 EDT? They look west to me.?

Using the funktop sat imagery, it looks as if the storm is moving 1 degree west about every 7 hours. Looking at the green appearing as what I think is the center and following that west ( although the green has gone away and I used the lighter red )is how I came to that conclusion. If I am right ( I'll appreciate any disagreement ) then it actually wobbled a slight bit s of due west.

when i posted the link they weren't updated and now i don't see the lines for the bam models yet.



Quoting hurricanejunky:
GFS shifting far east as well...



Mondays 18z Run.
she going WNW now
Quoting Jedkins01:


I heavily agree with you, thanks for the good analysis!




i hink thats a bout a 5% chance but we will see. Em looks like she is already moving more north and will cross hispanola farther east than projected
Intensity models continue to come up short.. Recon had 49kts in the vortex message, this lot didn't see anything that strong for atleast 24hrs.
15.4n63.7w has been re-evaluated&altered for the 6pmGMT ATCF
15.3n63.6w, 15.6n64.8w are now the most recent positions

TS.Emily's travel-speed was 13.8mph(22.3k/h) on a heading of 284.6degrees(WestNorthWest)

Copy&paste 15.0n58.5w, 15.1n60.5w-15.3n62.2w, 15.3n62.2w-15.3n62.8w, 15.3n62.8w-15.3n63.6w, 15.3n63.6w-15.6n64.8w, dom, ocj, 15.3n63.6w-18.08n76.3w into the GreatCircleMapper for more info

Using straightline projection of the travel-speed&heading derived from the ATCF coordinates for 12pmGMT then 6pmGMT :
TS.Emily was headed toward passing between LongBay and RuralHill,Jamaica ~4days7hours from now>
1555. jonelu
Just went to Habitat for Humanity Re-Do Center (WPB) for shutters. They were sold out on some of the more common window sizes. I have the old style clam shells on more than half the house. Bought the house June 6. Hopefully my area wont get more that TS winds because I still have 2 large windows and some sliders shutters to buy.
1556. jonelu
I think the broad LLC makes it easier for her to survive a pass over Hispanola.
1557. Patrap
18z Early Cycle NHC model tracks
Emily
Statistical/Simple Models (CLIPER,BAMs,LBAR,other Statistical Models)



Dynamic Models (More sophisticated models)




Models all shifting well offshore now...

Emily gonna be a fish storm now?


Afternoon again, all. Anybody else having trouble with the blog setup this afternoon? All the messages are showing as part of the first message for me...